Hi,
I am working with the STM32F103RCT6. I am writing a bare metal code for delay function using SYSTICK timer. The problem I am facing is that I am not able to write to the ARM cortex registers. Below is my code for your reference -
This is the stm32f103xx.h file
#define SYSCLK 8000000UL // System clock frequency in Hz
#define SYSTICK_BASE 0xE000E010UL
// SysTick Structure definition
typedef struct
{
volatile uint32_t CTRL; /* SysTick control and status register offset: 0x00 */
volatile uint32_t LOAD; /* SysTick reload value register offset: 0x04 */
volatile uint32_t VAL; /* SysTick current value register offset: 0x08 */
volatile uint32_t CALIB; /* SysTick calibration value register offset: 0x0C */
} SysTick_TypeDef;
#define SYSTICK ((SysTick_TypeDef *) SYSTICK_BASE)
This is the function in my main.c -
void SystemClock_Config(void)
{
__disable_irq(); // Disable all interrupts
// 1. Enable HSI
RCC->CR |= (1 << 0); // HSION = 1
// 2. Wait until HSI is ready
while (!(RCC->CR & (1 << 1))); // HSIRDY = 1
// 3. Select HSI as system clock
RCC->CFGR &= ~(0x3 << 0); // clear SW[1:0]
RCC->CFGR |= (0x0 << 0); // select HSI (00)
// 4. Wait until HSI is used as system clock
while ((RCC->CFGR & (0x3 << 2)) != (0x0 <<2) );
SYSTICK->LOAD = (uint32_t)((SYSCLK / 1000) - 1); // 1ms reload
SYSTICK->VAL = 0; // reset counter
SYSTICK->CTRL = (1U << 2); // processor clock enable
SYSTICK->CTRL |= (1U << 1); // enable interrupt
SYSTICK->CTRL |= (1U << 0); // enable SysTick
__enable_irq(); // Re-enable all interrupts
}This is the implementation of the SysTick_Handler . I debugged my code and the current_tick variable was not incrementing.
volatile uint32_t current_tick = 0;
void SysTick_Handler(void)
{
current_tick +=1;
}
Below is the screenshot of the cube programmer window after I flashed the code -
As you can see, the SYSTICK registers do not have the value I tried to write. My code only contains this piece of code which I shared. Is my code missing something that needs to be added or some other register that needs to be configured?
